The embodiments herein relate generally to oil production, and more particularly, to methods determining in-situ fluid distributions for oil fields using material balance and streamline-derived well-pair volumes.
Recovering oil from a mature flooded reservoir may be costly and prone to diminishing profits when managed inefficiently. Management decisions to efficiently recover oil from a mature flooded reservoir include changing well rates, drilling new wells, and converting existing production wells to injection wells or vice versa. These decisions hinge on an accurate estimate of the spatial distribution of remaining oil, gas, and water fluids, and pressure.
Current approaches use well-pair reservoir volumes that are defined manually and fixed in position for all time. The allocated fraction of injected/produced volumes into each well-pair is also usually assumed fixed in time since these allocations are estimated only from the geometry of the wells relative to each other. Fixed position well-pair reservoir volumes do not account for the dynamic nature of injection/production from an oil field and fail to account for opening new wells or closing old wells over time. The allocation of the fraction of volumes produced/injected in the fixed well-pair volume at the wells is estimated from the well positions only and does not account for well rates.
There is a need for a process that more accurately estimates the current distribution of fluids, and particularly oil in a reservoir.